小龙虾肌球蛋白在肌动球蛋白中不存在钙离子依赖性调节。

Crayfish myosin has no Ca2+-dependent regulation in actomyosin.

Watanabe K, Kitaura T, Yamaguchi M

J Biochem. 1982 Nov;92(5):1635-41. doi: 10.1093/oxfordjournals.jbchem.a134089.

Abstract

Crayfish myosin B lost Ca2+-dependent regulation in superprecipitation upon addition of pure rabbit skeletal F-actin. 2. Actomyosin reconstituted from crayfish myosin and pure rabbit skeletal F-actin showed both Ca2+-dependent regulation in superprecipitation and Mg2+-ATPase activity upon addition of native tropomyosin prepared from crayfish or rabbit skeletal muscles. Also, superprecipitation of this actomyosin was induced by ITP without Ca2+-dependent regulation, as is the case in rabbit skeletal actomyosin. 3. Actomyosin reconstituted from crayfish native thin filament and crayfish or rabbit skeletal myosins showed Ca2+-dependent regulation. 4. These findings indicate that crayfish myosin is similar to rabbit skeletal myosin and different from chicken gizzard myosin in regulatory function.

摘要

加入纯兔骨骼肌F-肌动蛋白后，小龙虾肌球蛋白B在超沉淀中失去了Ca2+依赖性调节。2. 由小龙虾肌球蛋白和纯兔骨骼肌F-肌动蛋白重构的肌动球蛋白，在加入从小龙虾或兔骨骼肌制备的天然原肌球蛋白后，在超沉淀中显示出Ca2+依赖性调节以及Mg2+-ATP酶活性。此外，这种肌动球蛋白的超沉淀由肌苷三磷酸（ITP）诱导，且无Ca2+依赖性调节，这与兔骨骼肌肌动球蛋白的情况相同。3. 由小龙虾天然细肌丝与小龙虾或兔骨骼肌肌球蛋白重构的肌动球蛋白显示出Ca2+依赖性调节。4. 这些发现表明，小龙虾肌球蛋白在调节功能上与兔骨骼肌肌球蛋白相似，而与鸡胗肌球蛋白不同。